The present invention relates to an apparatus for desulfurization of flue gas and, in further detail, an apparatus for desulfurization of flue gas in which the sulfurous acid component in the flue gas is made to contact with and be absorbed by an absorption liquid and simultaneously is oxidized by an oxygen-containing gas and fixed by a fixing reactant in the absorption liquid.
In the wet-type flue gas desulfurization, the method of absorbing sulfurous acid gas and oxidizing it simultaneously with an oxygen-containing gas has been considered as one of the best systems to simplify the equipment from the beginning of development. Its realization has been an important target. A problem in perfecting this system is to cause oxygen to be absorbed since it has an absorption rate lower than sulfurous acid gas. For this reason, conventionally for flue gas of small volume, or for flue gas with sulfurous acid gas concentration of as low as about 100 ppm, an oxygen containing gas is blown into the flue gas to cause absorption and oxidation in the flue gas; no practical technique of applying this knowlege to large volumes of flue gas has been established, heretofore, because equipment would be too large.